The present invention relates to a disposable canister, and more particularly to a light-tight canister for protecting a roll of core wound photosensitive media, containable therein, from being damaged or exposed to actinic light.
In the operation of a microfiche or microfilm reader-printer of, for example, the type illustrated in U.S. Pat. No. 4,302,102, a photosensitive media is fed from a roll as needed during production of enlarged copies of preselected images of the micofiche or microfilm. Because of the difficulty in loading reader-printers in lighted areas, they are capable of accepting preloaded light-tight canisters. These preloaded canisters, of the type illustrated in U.S. Pat. Nos. 4,431,139, 4,291,802, 3,756,392 and 3,532,210, are placed in the reader-printer and the photosensitive media is dispensed therefrom as needed while the canister prevents the unused portion of the media from being exposed. However, there are several problems and limitations associated with such prior canisters.
One particular problem has been associated with the undesired rotation of the roll of media, including blooming, during shipping and storing which can result in tearing, folding or other damage to the media. One specific attempt to prevent the problems associated with blooming has been by providing a locking member that co-operates with the core of the roll and the wall of the canister. The locking member has a weakened zone which can be ruptured by the torsional force applied to the locking member when the user starts pulling the media from the canister, as illustrated in U.S. Pat. Nos. 4,403,845 and 4,398,814. However, a canister utilizing such a locking member is difficult and time consuming to assemble in a red-light room or darkroom.
In addition to the above, contamination of the photosensitive media by actinic light entering the exit slot has been a problem. Several approaches have been proposed in an attempt to solve this problem, namely that the exit slot be formed of mated, curved lips, as illustrated in U.S. Pat. Nos. 4,291,802 and 4,239,164, or that a strip of material be applied across the exit slot, as illustrated in U.S. Pat. No. 3,532,210, or that a plush be placed along the exit slot, as described in U.S. Pat. No. 4,239,164. However, both canisters utilizing these proposals require additional time to assemble either in a red-light room or darkroom, or subsequently outside of it subjecting the media to possible exposure. In addition, neither prevents blooming of the media.
Another problem associated with prior canisters is that of media accessibility. In one such canister, the end of the core wound media extends out of the canister through the exit slot and is attached to the exterior of the canister by adhesive tape or the like to prevent it from being pulled into the canister where it would become inaccessible, as illustrated in U.S. Pat. No. 3,532,210. However, the use of such adhesives and the like make the canister more difficult and time consuming to assemble in either a red-light room or darkroom, or subsequently outside of it increasing the possibility of the extending portion of the media becoming inaccessible.
The canisters as discussed above do not describe a canister including a light sealing, anti-blooming tab which can be assembled and preloaded in a red-light room or darkroom with a minimum of difficulty, and which prevents the extending end portion of the media from being pulled back into the canister where it would become inaccessible.